(1) Field of the Invention
This invention relates to a method for putting a time code in asynchronously transmitted data. More specifically the invention relates to a method for providing a time code for multiple streams of simultaneously received data in order to allow reconstruction of the data after asynchronous transfer.
(2) Description of the Prior Art
It is often desirable to transmit data collected from a plurality of sensors. When the data is received, it is desirable that the original signal be reconstructed to have the same timing as the originally received data. Asynchronous transfer mode (ATM) utilizes a shared, high bandwidth transmission line. In ATM, data is packaged into 53 Byte cells having a 5 Byte header and a 48 Byte data region. When data is transmitted via ATM, other data is inserted in the transmission stream and the timing of the transmitted data is not preserved. Additionally, data cells can be lost during transmission. If detected, various well known error correction techniques can be applied to make up for the lost data.
The prior art discloses numerous means for capturing the time that a single data stream is received. Typically, these methods involve adding a time stamp to each cell transmitted over an ATM network. These methods do not allow time reconstruction of data received simultaneously from a plurality of data sources because they do not include a means for synchronizing data among the sources to indicate both the time received and the source.